A (2-phosphinoethyl)silylrhodium(III) complex RhH(Cl)[(κ2Si,P)-Me2Si(CH2) 2PPh2](PMe3)2 (1) was synthesized by the thermal reaction of RhCl(PMe3)n (n = 3, 4) with HMe2Si(CH)2PPh2 at 50°C for 2 h. Treatment of 1 with MeLi gave a coordinatively unsaturated rhodium(I) complex Rh[(κ2Si,P)-Me2Si(CH2)2PPh 2](PMe3)2 (2) which was possibly produced via transient formation of RhH(Me)[(κ2Si,P)-Me2Si(CH2) 2PPh2](PMe3)2 and subsequent reductive elimination of methane. X-Ray crystal structure analysis revealed that 2 adopts a slightly distorted square planar geometry. When the reaction of 1 with MeLi was carried out in the presence of PMe3, a coordinatively saturated silylrhodium(I) complex Rh[(κ2Si,P)-Me2Si(CH2)2PPh 2](PMe3)3 (3) was formed. According to the X-ray crystal structure analysis, 3 adopts a five-coordinate, slightly distorted trigonal-bipyramidal arrangement in which the silyl silicon atom and a PMe3 ligand occupy the axial positions. Variable temperature NMR measurements revealed that both 2 and 3 undergo the exchange of PMe3 ligands on the NMR timescale. The exchange in 2 is intramolecular, while that in 3 is intermolecular. Treatment of HSiMe2Ph with 2 gave rise to selective dehydrogenative coupling of hydrosilanes to afford (SiMe2Ph)2 and RhH2[(κ2Si,P)-Me2SiCH2CH 2PPh2](PMe3)2 (5).
|Number of pages||8|
|Journal||Journal of the Chemical Society, Dalton Transactions|
|Publication status||Published - 2002 May 22|
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